Repair 7

Carrying Away Engine Exhaust Gases

Headers are typically installed on cars by a vehicle owner seeking to increase the horsepower of his cars engines. Headers are simple exhaust tubes or exhaust pipes that allow for the faster exiting of burned engine exhaust gases. Traditional exhaust manifolds are somewhat restrictive to exiting engine exhaust gases and create a bit of engine backpressure, which reduces engine horsepower and restricts gas mileage. Headers, on the other hand, typically have larger exhaust tubing and special tubing designs that enable exhaust gases to exit a cars engine faster and in greater quantities. This leads to a reduction in engine backpressure and an increase in both engine horsepower and gas mileage.

Bolt Headers to Engine Exhaust Ports

Automotive headers, which take the place of factory-installed exhaust manifolds, simply bolt directly to an engines exhaust ports, which are the openings in a cars engine through which exhaust gases flow out. Headers have flat areas (header flanges) on their exhaust tubing ends that align directly against the side of a cars engine exhaust ports. Header bolts attach directly through the header flanges and create an airtight seal, through which exiting engine exhaust gases travel directly into engine headers.

Funneling Exhaust to Remaining Exhaust Components

As exiting engine exhaust gases flow through a set of headers, these exhaust gases are transported to the remaining components of a cars exhaust system. Headers, besides allowing exhaust gases to exit a cars engine faster and in greater quantities, serve to bridge the gap between the engine and its main exhaust system components. Normally, exhaust gases, after flowing through and exiting a set of headers, travel to a cars catalytic converter, where these exhaust gases are reignited and burned. After traveling through the catalytic converter, exhaust gases travel through a cars muffler and then out of the tail pipe.

Car headers, which attach to the sides of a vehicle engine, are an important part of a vehicles exhaust system. Made up of solid steel tubing, headers are the first parts of a vehicles exhaust system to come into contact with exiting engine exhaust gases.

Link Engine to Exhaust System

Headers are long, tubular metal pipes that bolt to the sides of an engine. Headers line up with the engine exhaust ports and provide a link through which exiting engine exhaust gases flow out of an engine and towards the inner exhaust system.

Collect Engine Exhaust Gases

As burned engine exhaust gases exit an engine, headers collect these gases and funnel them down the header pipes and into the main exhaust system, which is where the muffler and catalytic converter reside.

Transport Engine Exhaust Gases

Headers serve as a critical link between a vehicles exhaust system and its engine. As engine exhaust gases flow through a set of headers, the headers direct these gases to the main vehicle exhaust pipe, where they flow through the exhaust muffler and catalytic converter.

Temper Exhaust Sound

Headers also serve to dampen and temper the sound of a vehicles exhaust system. By providing a solid, tubular enclosure for exiting engine exhaust gases, headers help mask some of the popping and crackling sounds of high-speed, high-temperature exhaust gases.

Reduce Exhaust Gas Speed

As exhaust gases exit a vehicles engine, they travel at very high rates of speed. Headers present the first physical barrier to these exiting exhaust gases, a situation that serves to slow down their rate of speed as well as increase the efficiency of both the vehicle muffler and catalytic converter.

The size of an exhaust header pipe should match the needs of a particular vehicle. You can find the size of a header pipe by performing a simple math equation. To do this you first need to obtain variables to use in the equation. These variables include the engines cubic inch displacement, its maximum revolutions per minute and the outside diameter of the header tube. You can find the variables for the equation by referencing your owners manual or a repair manual for the vehicle.

Instructions

1

Write the equation for calculating pipe header size. This is expressed as L = CID x 1900/RPM x OD.

2

Input the cubic inch displacement of the engine for CID. Input the maximum RPM of the engine into the equation. Input the Outside Diameter of the header tube for OD in the equation.

3

Multiply the CID by 1900 and note the result. Multiply the maximum engine RPM by the OD and note the result. Divide the first result by the second result to obtain the size of the pipe header.